Protecting data in a networked system is critical. The types of situations that can corrupt or otherwise affect the integrity of valuable data are numerous and increasing as network systems evolve. When an event occurs that affects the integrity of data, it is important to be able to detect that the event occurred. Otherwise, as is often the case, the data remains in its affected state, and the network remains vulnerable to the same type of event in the future.
The types of problems modern networks face in protecting valuable data include, for example, hack attacks and other data corruption from unauthorized use, disasters, malware (such as viruses and trojan horses), hardware or software failure, insider fraud or misuse, and human error (such as unintentional data entry mistakes).
Different approaches have been developed for some of the common problems encountered by networked systems. For example, firewalls and virtual private networks guard networked systems against unauthorized access from external sites. The designation of privileges provide some protection against what actions different classes of users may take on the network. In this respect, the designation of privileges may protect against insider fraud and misuse. Data backups provide protection in the event of a hardware or software failure. However, in most cases, if a problematic event circumvents the various protective mechanisms of a particular network and damages or otherwise affects the network's data, the affected data is not readily identifiable, especially if the event is not subsequently noticed.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.